1. Field of the Invention
The present invention relates to a connection terminal that electrically connects to a terminal by coming into contact with the terminal, and to an AC adapter including the connection terminal.
2. Description of the Related Art
AC adapters that supply power to electronic apparatuses (such as portable electronic devices) include AC adapters usable worldwide with commercial supply voltages of various regions. (See, for example, FIG. 1.)
FIG. 1 is an exploded plan view of a conventional AC adapter.
Referring to FIG. 1, a conventional AC adapter 200 includes a power supply plug 201, an upper case 202, a circuit board 204, electronic components 205, connection terminals 207, and a DC cord 208.
The power supply plug 201 includes a lower case 211 and pin plugs 212, which are terminals. The lower case 211 has an attachment groove part (not graphically illustrated) for attachment of the circuit board 204.
Each of the pin plugs 212 has a rod shape, and has an outlet insertion part 215 at one end and a connection part 216 at the other end. The outlet insertion part 215, which is configured to be inserted into an outlet, is exposed outside the lower case 211. The connection part 216, which is configured to be held by the corresponding connection terminal 207, projects from the interior wall of the lower case 211.
The upper case 202 includes a housing part 218 for housing the circuit board 204 on which the electronic components 205 and the connection terminals 207 are mounted. The upper case 202 further includes a pair of guides 219 configured to guide the circuit board 204.
FIG. 2 is a partial cross-sectional view of the structure of FIG. 1, taken along the line and in the direction indicated by arrows J.
Referring to FIG. 2, the circuit board 204 includes a board body 222 having a mounting surface 222A; an interconnection pattern 223 provided on a surface 222B of the board body 222 on the opposite side from the mounting surface 222A; and a solder resist layer 224 having an opening 224A that exposes part of the interconnection pattern 223 that corresponds to a region where solder 226 is formed.
Referring back to FIG. 1, the electronic components 205 are mounted on the mounting surface 222A of the board body 222. The electronic components 205 are electrically connected to the interconnection pattern 223.
Examples of the electronic components 205 include a capacitor, a transformer, and a switching device.
Referring to FIG. 1 and FIG. 2, the connection terminals 207 are provided in part of the peripheral part of the circuit board 204 which part faces the power supply plug 201. The connection terminals 207 are provided at such positions as to allow the connection terminals 207 to hold the connection parts 216 of the corresponding pin plugs 212. Each of the connection terminals 207 includes a fixing part 231 and a pair of elastically deformable pieces 233.
The fixing part 231 includes a support part 235 that supports the elastically deformable pieces 233, and an electrical connection part 236 that penetrates through the board body 222 and the interconnection pattern 223. The electrical connection part 236 is fixed to the interconnection pattern 223 with the solder 226. Thereby, the connection terminals 207 are electrically connected to the circuit board 204.
FIG. 3 is a cross-sectional view schematically illustrating the connection terminal 207 holding the connection part 216 of the corresponding pin plug 212. FIG. 4 is a diagram illustrating the structure illustrated in FIG. 3 viewed in the direction indicated by arrow K. In FIG. 3 and FIG. 4, the same elements as those of the structure illustrated in FIG. 2 are referred to by the same numerals.
Referring to FIG. 3 and FIG. 4, the elastically deformable pieces 233 are provided on the support part 235 so as to face each other. The elastically deformable pieces 233 include respective contact parts 238 that project toward the center of the elastically deformable pieces 233. The contact parts 238 electrically connect the circuit board 204 and the pin plug 212 by holding the connection part 216 of the pin plug 212 inserted in the connection terminal 207.
Referring to FIG. 1, the DC cord 208 has one end connected to the circuit board 204. Thereby, the DC cord 208 is electrically connected to the electronic components 205, the connection terminals 207, and the circuit board 204. The DC cord 208 has, at the other end, a plug 241 to be connected to an electronic apparatus (not graphically illustrated).
The AC adapter 200 configured as described above converts alternating current (AC) power into direct current (DC) power, and supplies the DC power to the electronic apparatus (not graphically illustrated). (See, for example, Japanese Laid-Open Patent Application No. 11-224717.)